// Tencent is pleased to support the open source community by making ncnn available.
//
// Copyright (C) 2017 THL A29 Limited, a Tencent company. All rights reserved.
//
// Licensed under the BSD 3-Clause License (the "License"); you may not use this file except
// in compliance with the License. You may obtain a copy of the License at
//
// https://opensource.org/licenses/BSD-3-Clause
//
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.

#include "absval_arm.h"

#if __ARM_NEON
#include <arm_neon.h>
#endif // __ARM_NEON

void *AbsVal_arm_ctor(void *_self, va_list *args)
{
    Layer *self = (Layer *)_self;

#if __ARM_NEON
    support_packing = true;
#endif // __ARM_NEON

    return _self;
}

int AbsVal_arm_forward_inplace(Mat& bottom_top_blob, const Option& opt)
{
    int w = bottom_top_blob.w;
    int h = bottom_top_blob.h;
    int channels = bottom_top_blob.c;
    int size = w * h;
    int elempack = bottom_top_blob.elempack;

#if __ARM_NEON
    if (opt.use_packing_layout)
    {

    if (elempack == 4)
    {
        #pragma omp parallel for num_threads(opt.num_threads)
        for (int q=0; q<channels; q++)
        {
            float* ptr = bottom_top_blob.channel(q);

            for (int i=0; i<size; i++)
            {
                float32x4_t _p = vld1q_f32(ptr);
                _p = vabsq_f32(_p);
                vst1q_f32(ptr, _p);

                ptr += 4;
            }
        }

        return 0;
    }

    } // opt.use_packing_layout
#endif // __ARM_NEON

    #pragma omp parallel for num_threads(opt.num_threads)
    for (int q=0; q<channels; q++)
    {
        float* ptr = bottom_top_blob.channel(q);

#if __ARM_NEON
        int nn = size >> 2;
        int remain = size - (nn << 2);
#else
        int remain = size;
#endif // __ARM_NEON

#if __ARM_NEON
#if __aarch64__
        if (nn > 0)
        {
        asm volatile(
            "0:                               \n"
            "prfm       pldl1keep, [%1, #128] \n"
            "ld1        {v0.4s}, [%1]         \n"
            "fabs       v0.4s, v0.4s          \n"
            "subs       %w0, %w0, #1          \n"
            "st1        {v0.4s}, [%1], #16    \n"
            "bne        0b                    \n"
            : "=r"(nn),     // %0
              "=r"(ptr)     // %1
            : "0"(nn),
              "1"(ptr)
            : "cc", "memory", "v0"
        );
        }
#else
        if (nn > 0)
        {
        asm volatile(
            "0:                             \n"
            "vld1.f32   {d0-d1}, [%1]       \n"
            "vabs.f32   q0, q0              \n"
            "subs       %0, #1              \n"
            "vst1.f32   {d0-d1}, [%1]!      \n"
            "bne        0b                  \n"
            : "=r"(nn),     // %0
              "=r"(ptr)     // %1
            : "0"(nn),
              "1"(ptr)
            : "cc", "memory", "q0"
        );
        }
#endif // __aarch64__
#endif // __ARM_NEON
        for (; remain>0; remain--)
        {
            *ptr = *ptr > 0 ? *ptr : -*ptr;

            ptr++;
        }
    }

    return 0;
}
